Two-layer expansible linkage with laterally engaged links



April 12, 1960 AKIRA NABESHIMA 2,932,155

TWO-LAYER EXPANSIBLE LINKAGE WITH LATERALLY ENGAGED LINKS Filed May 19, 1955 2 Shets-Sheet 1 IN V EN TOR. Ame/4 NABESl/Mlfl Anne/#75 April 12, 1960 AKIRA NAB'ESHIMA, ,155

TWO-LAYER EXPANSIBLE LINKAGE WITH LATERALLY ENGAGED LINKS Filed May 19, 1955 2 Sheets-Sheet 2 V EN TOR. AKAGA /V BY mg; W M; %&W

TWO-LAYER EXPANSIBLE LINI AGE WITH LATERALLY ENGAGED LINKS Akira Nabeshima, Koto-ku, Tokyo, .lapan Application May 19, 1955, Serial No. 509,612 1 Claim. (CI. 59-79) This invention relates to an improvement ina metallic expansion band, such' as a band for use in a wrist watch.

The object of this invention is to provide a metallic expansion band allowing a smooth operation thereof without danger of breakage and making it smartness in the appearance owing to the absence of any remarkable gap on the end surfaces thereof even when the band is extended, by the use of a connecting plate having hooked portions at its tip ends to be engaged the free ends of two springs as opposing each other enclosed in the each band section and also by providing downwardly bent portions on both ends of the band sections loosely overlapping vertical end walls of the connecting plate.

This invention consists of a metallic expansion band comprising a series of band sections each having downwardly bent end portions so as to close openings at its both ends, and a series of connecting plates each having hooked portions at its upper ends to engage free ends of two springs enclosed in the band section and being arranged slidably below and between two adjacent band sections.

Also, according to the present invention, the metallic expansion band comprises a series of band sections each consisting of an outer cover plate and an inner reinforcing plate fixed thereto so as to form a rectangular body having downwardly bent end portions at its both ends, and a series of connecting plates each including a base portion and a back plate and having hooked portions at its upper ends to engage free ends of two springs as opposing each other enclosed in the band section and also being arranged slidably below and between two adjacent band sections, said back plate being fixed to the lower side of the base portion by means of stop nibs and having flanges at its both ends bent upwardly so as to overlap the end walls of the base portion.

According to the present invention, the metallic expansion band comprises a series of band sections each having downwardly bent portions so as to close openings at its both ends, and a series of connecting plates each including a base portion and a back plate and having hooked portions at its upper end to engage free ends of two springs as opposing each other enclosed in the band section, each of said connecting plates being arranged slidably below and between two adjacent band sections and having upwardly bent vertical end walls loosely positioned between the downwardly bent end portion and the inner reinforcing plate of the band section and also being held resiliently by the engagement of the hooked portions of 2,932,155 Patented Apr- Fig. 1 is a plan view of the band partly in a sectlon taken along line 1-1 of Fig. 2; 1

Fig. 2 is a side view of the band partly in a longitudinal section;-

Fig. 3 is a sectional view of the band taken along line .JCQ

III-III of Fig. l;

the connecting plate with the free ends of said springs so Fig. 4 is a side view of the band partly in a longitudinal section showing an extended state thereof;

Fig. 5 is a perspective view of a cover plate of the band section; I I

Fig.6 is a perspective view of a spring';

Fig.7 is a perspective view of a connecting plate; 1

Fig. 8 is a perspective view of a back plate. In the drawings-each of band sections 1 is made of a hollow rectangularform. in cross section and is formed by pressing an inner reinforcing plate 2 of a channel form opened at its both ends into an outer cover plate 3 of a channel form so as to embrace in each other from up and down thereof to form a hollow rectangular shape and by bending stop nibs 4, 4, 4, 4 provided on side edges of the outer cover plate 3 upon the inner reinforcing plate 2 so as to fix them together.

In each of the band sections, there is provided with two springs 5, 5 as opposing each other so as to force their,

free both ends in the direction toward the middle part of the band section 1. A connecting plate 6 for connecting successively the springs 5, 5 is made of approximately the same length as that of the band section 1 and has its base portion 7 arranged so as to extend over the border part of the back side of the adjacent band sections and also has both vertical end walls 8, 8 bent upwardly at a right angle from the base portion 7. Said vertical end walls 8, 8 have at their upper ends two hooked portions 9, 9 respectively which are projected inwardly so as to engage with the free ends of the springs in each of the adjacent band sections. The base portion 7 of the connecting plate 6 is bent upwardly in the shape of an arch and has underneath thereof fixed a back plate 10. Said back plate 10 is fixed on the base'portion 7 by bending stop nibs 11, 11, 11, 11 projected from the both sides of the back plate 10 upon the base portion 7. Said back plate 10 also has at its both ends flanges 12, 12 bent upwardly therefrom so as to overlap the corresponding end walls 8, 8 of the base portion 7 of the connecting plate 6.

Said all the members after assembled are finished as a complete expansion band by bending the both extending end portions 13, 13 of the cover plate 3 at a right angle along the vertical end walls of the connecting plate 6. In order to facilitate the insertion and removal of the hooked portions 9 for the both ends of the band section 1, the connecting plate 6 may be cut oif at its middle portion, and said cut end portions of the connecting plate may be inserted from the respective end of the tubular end section so as to engage therein and be retained thereat by suitable means, such as a pin and a hole. Also, 14 shows a mounting ring for the wrist watch.

As above described, according to the present invention, each of the band sections comprises two springs in the interior thereof, and expansion is being performed by utilizing the elasticity of said spring plates, thereby allowing a large latitude in expansion as well as smooth operation thereof, therefore, it can afford much comfort in the use of the expansion band as disclosed in this invention. As further advantages obtainable in this invention, since the border part of the band is covered up by the connecting plate, smartness is gained in the appearance, and besides, it can be offered at a moderate cost owing to its simple construction.

What I claim is:

A metallic expansion band comprising a series of tubularv band sections each having downwardly bent portions so .as to closeopenings atits both ends, said ends being positioned in planes substantially parallel to the axis of said metallic expansion band, and a series of connecting plateseach' including a base portion and a back plate and having hooked portio'ns at its upper end to engage free ends of'each of two transverse opposed springs centrally pivoted and freely enclosed in two adjacent band sections and biasing said two adjacent band sections toward each other, each of said connecting plates being arranged slidably below and between two adjacent band sections, an inner reinforcing plate for each band section, each of said connectingplates having upwardly bent end walls loosely positioned between the downwardly bent end portion and an inner reinforcing plate of the corresponding band section and also being held resiliently by the engagement of the hooked portions of the connecting plate with the free ends of said springs 80 that the length of the band is extended or shortened,

References Cited in the file of this patent UNITED STATES PATENTS 1,426,884 Levy Aug. 22, 1922 1,708,466 Brandt Apr. 9, 1929 1,712,582 Renz May 14, 1929 1,730,105 Whiting Oct. 1, 1929 2,430,776 Miller Nov. 11, 1947 2,528,568 Williams Nov. 7, 1950 FOREIGN PATENTS 89,439 Switzerland June 4, 1920 212,479 Great Britain Mar. 3, 1924 257,309 Switzerland Sept. 30, 1948 623,391 Great Britain .a.....-......- May 17, 1949 

